Bolshoy Shantar is an island in the Sea of Okhotsk, Russia. It is the main island of the Shantar Islands. Its area is 1766 km². It is about 72 km in length and 49 km in width. It has a large brackish lake (Lake Bol'shoe) in its northern end which is connected to the sea through a narrow passage. Smelts (Hypomesus japonicus) and (H.